As many as 86 Atlanta-based workers for the Centers for Disease Control and Prevention may have been unintentionally exposed to anthrax , the agency says . This includes people who have come forward since the announcement Thursday , saying they were in the area during the time of exposure .

The workers are being monitored or provided antibiotics .

`` Based on most of the potential exposure scenarios , the risk of infection is very low , '' the agency said in a statement .

`` CDC believes that other CDC staff , family members , and the general public are not at risk of exposure and do not need to take any protective action . ''

As of Thursday afternoon , the agency 's Occupational Health Clinic had seen 54 employees identified to have been in the labs or hallways at the time of exposure , according to CDC spokesman Tom Skinner .

Of the 54 who have already been seen , Skinner said only two chose not to take oral antibiotic treatment . In addition to taking antibiotics to ward off any possible anthrax infection , the CDC says 27 staffers have received the anthrax vaccine .

Skinner says remaining identified employees , who have not yet been evaluated at their clinic , are scheduled to be seen Friday .

Early reports show that a lab did not adequately inactivate samples , which were then moved and used for experimentation in three laboratories not equipped to handle live Bacillus anthracis , or anthrax .

Believing the samples were inactivated , workers in those labs did not don adequate protective equipment , the CDC said .

The unintentional exposure was discovered on June 13 .

What to know about anthrax

Sometime between then and June 6 , procedures in two of the three labs may have aerosolized the spores , the CDC said . Hallway and lab areas were decontaminated .

There are three types of anthrax infection : cutaneous -LRB- through the skin -RRB- , inhalation -LRB- through the lungs -RRB- and gastrointestinal -LRB- through digestion -RRB- .

Early symptoms can suggest the flu .

`` In the worst-case scenarios , literally , within a day or two of exposure , if you 've inhaled spores and if they are very lethal , one begins to get -- as they say -- the standard flu symptoms -- high fever , malaise , '' said Leonard Cole , a bioterrorism expert . `` You get lazy . You feel sick . You get headaches . You get bone aches .

`` And then after a day or two , in the worst case , if you do n't get treatment , it could be lethal for you , and beyond treatment , '' he said .

The CDC said disciplinary action , as necessary , will be taken . The agency will review safety protocol with employees .

The Federal Bureau of Investigation is aware of the incident and coordinating with officials at the CDC as they investigate , said FBI spokesman Christopher Allen .

`` It is CDC 's obligation to ensure that people feel safe and are safe in the workplace and the community as we conduct our life-saving laboratory work . We will report findings of this investigation and all steps we take to improve lab-safety processes as a result of this incident , '' the agency 's statement said .

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As many as 86 Atlanta CDC workers may have been exposed to anthrax

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The FBI is coordinating with CDC officials as they investigate

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There are three types of anthrax infection ; early symptoms can suggest flu

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Workers are being monitored or provided antibiotics , and there 's no risk to the public , CDC says